Eastern Speckled Shield Lichen

(Punctelia bolliana)

               
Conservation Status

IUCN Red List

not listed

Eastern Speckled Shield Lichen

NatureServe

NNR - Unranked

Minnesota

not listed

Occurrence

Very common

Habitat/Hosts

Open woodlands, fields, and roadsides; deciduous trees

 

 

    Photo by Luciearl
 
Identification

Eastern Speckled Shield Lichen occurs across North America but is especially common in central United States. It is very common in Minnesota. It is found in open woodlands, fields, and roadsides. It grows on the bark of deciduous trees.

The vegetative body (thallus) is leaf-like (foliose), bluish-gray, and divided into branches (lobes). The lobes are small to medium-sized, mostly 1 16 to ¼ (2 to 6 mm) but up to (10 mm) in diameter. On older parts of the thallus, the lobes become wrinkled and folded and develop many small lobe-like growths (lobules) both on the edges and across the surface. The upper surface does not have powdery dull granules (soredia), shiny granules (isidia), or a chalky or “frosted” surface (pruina). However, it does have abundant, tiny, globular chambers (pycnidia) embedded in the thallus with an opening through which fungal spores are released. The pycnidia look like pale brown to black pinpricks on the thallus surface. The lower thallus surface is pale tan and is covered with pale unbranched anchoring structures (rhizines) up to the lobe edges.

Brown, slightly raised, disk-like, spore-producing structures (apothecia) are always present, usually abundant. The disks are broad, to (3 to 15 mm) in diameter, and are shaped like a plate with a ring around them. They are brown inside and the ring is made of tissue similar to the thallus. Larger disks often have a convoluted shape.

 
Similar
Species

 

 
Distribution Distribution Map  

Sources: 4, 7, 24, 26, 29, 30, 77.

 
Comments

What’s in a Name?
The “speckled” in the common name refers to the abundant, tiny, dark, pycnidia on the upper surface of the thallus.

 
Taxonomy

Division:

Ascomycota (sac fungi)

 

No Rank:

saccharomyceta

 

Subdivision:

Pezizomycotina

 

No Rank:

leotiomyceta

 

Class:

Lecanoromycetes

 

Subclass:

Lecanoromycetidae

 

Order:

Lecanorales

 

Suborder:

Lecanorineae

 

Family:

Parmeliaceae

 

Mycobiont:

Punctelia bolliana

 

Photobiont:

green (Treboixia?)

 
Synonyms

Parmelia bolliana

 
Common
Names

Eastern Speckled Shield Lichen

 

 

 

 

 

Glossary

Apothecium

An open, disk-shaped or cup-shaped, reproductive structure, with spore sacs on the upper surface, that produces spores for the fungal partner of a lichen. Plural: apothecia.

 

Foliose

Adjective: Leaf-like growth form; referring to lichens with leaf-like growths divided into lobes.
Noun: The leaf-like, vegetative body of a lichen (thallus) that has thin, flat lobes which are free from the substrate.

 

Isidium

The reproductive structure of a lichen consisting of a cluster of algal cells (the photobiont) wrapped in fungal filaments (the mycobiont) and enclosed within a layer of protective tissue (cortex). Plural: isidia.

 

Lobule

A small lobe-like subdivision of a lobe. In lichens, a small lobe-like, asexual, reproductive structure produced at the edge of a lobe, breaks off, and reestablishes elsewhere.

 

Rhizine

A root-like structure of a lichen that attaches the lower layer to the substrate.

 

Soredium

The reproductive structure of a lichen consisting of a cluster of algal cells (the photobiont) wrapped in fungal filaments (the mycobiont). Plural: soredia.

 

Thallus

The vegetative body of a lichen composed of both the alga and the fungus.

       
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Luciearl
       
  Eastern Speckled Shield Lichen   Eastern Speckled Shield Lichen
       
  Eastern Speckled Shield Lichen    
       
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Luciearl
2/12/2019

Location: Cass County

Eastern Speckled Shield Lichen


     
     
 
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Created: 2/15/2019

Last Updated:

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